Tennis ball

It's hard to believe that the courtly game of tennis has been around for nearly 1000 years. Since its inception in 12th century France, it has evolved constantly into the fast-paced serve and volley game that we know today. At the very center of that evolution is the game's most important component: the tennis ball.

The very first tennis balls were made of leather and stuffed with wool or fur. They were often very hard, and a number of serious injuries came about as a result of an energetic game of tennis. It was not uncommon to hear about a lady or lord being struck and killed by an errant smash!

By the 18th century, the ball had changed into a rough version of today's tennis ball: small bits of wool were rolled up into a little ball, and then a piece of string was wrapped around this core. Finally, the entire ball was placed inside a small cloth cover. These balls were acceptable on clay and wooden courts, but with the advent of lawn tennis (essentially the modern game you see today), springier balls were needed. Luckily, Charles Goodyear's vulcanization process gave the game what it needed: bouncy rubber cores.

From then until now, modern tennis balls have only seen minor changes, the most predominant one being the fuzzy yellow exterior (made of wool and called felt) that replaced the less resilient cloth overlays of the past. Ever wondered why tennis balls are yellow? It's one of the easier colors for television cameras to spot.

Today you can buy tennis balls in two main varieties: pressureless and pressurized. Generally, pressureless balls are good for ball machines, or drills involving repeating the same stroke over and over. They are a lot cheaper than pressurized balls, making them ideal for tennis drills and camps. Pressurized balls (like the ones you buy in cans three at a time) are better for playing real games, because they are livelier and less likely to break under the stress of repeat hitting.

The major tennis ball manufacturers in the world are Wilson, Prince, Slazenger, and Penn. The ubiquitous yellow orbs have seen use as pet toys, science project subjects, walker supports, explosives, and massagers. A free household hint: throw your old tennis balls in the dryer with your blankets and pillows to cut down on drying time and get rid of lumps.